In order to replace a missing tooth or a tooth having a degraded function, dental clinics or dental laboratories manufacture an artificial tooth and use a zirconia material in general.
A zirconia artificial tooth has advantageous in that it has excellent biocompatibility, a greater aesthetic function than a metal, and high mechanical properties (flexure strength of 1,000 MPa or more and fracture toughness of 9 to 10 MPa·m1/2), it has high productivity since it can be automatically produced using a dental CAD/CAM system, and it can be used both in an anterior region and a posterior region.
When an artificial tooth is manufactured using zirconia, it is very important to preserve aesthetics by producing it to have a color as similar as possible to a natural tooth. In general, a tooth has various colors, and a color guide is used as a reference in many cases.
In a commonly used color guide, colors are classified as A series, B series, C series, D series, or the like. Even when a natural tooth belongs to A series, a concentration of the color is subdivided into a root of a tooth of A3, a body of A2, a cusp of A1, and the like. In order to express them, porcelain powder, a liquid color set, or the like is used.
Since a zirconia block color in the related art has a very simple form expressing white or only one particular color, in order to express the same color as a real natural tooth, several complex processes such as a pigment treatment and a surface treatment are necessary after the zirconia block is processed.